WASHINGTON (Reuters) - The U.S. Treasury Department said on Friday it received $556.7 million in proceeds from auctions to sell warrants in 11 major U.S. airlines the government received in exchange for COVID-19 assistance.

The proceeds are a fraction of the total assistance awarded to airlines.

Congress approved $54 billion in COVID-19 air carrier bailouts in 2020 and 2021. Airlines were required to repay $14 billion of that total and Treasury received warrants to purchase stock at the share price of the time of the awards.

The warrants expire between April 2025 and June 2026.

Treasury had set revised minimum prices for the warrants of $458 million in total. A Treasury spokesperson said the government plans to publicly announce the individual auction sale prices later this summer.

American Airlines ( AAL ) received $12.6 billion in government assistance, followed by Delta $11.9 billion, United Airlines $10.9 billion, and Southwest ( LUV ) at $7.2 billion.

Seven other airlines received smaller awards, including $2.2 billion for Alaska Airlines.

Treasury set reserve prices of $221 million for its Delta warrants, $159 million for United, $25 million for American Airlines ( AAL ), $30 million for SkyWest ( SKYW ), $17 million for Alaska Air, $2.7 million for Hawaiian Airlines, $1.9 million for Frontier Group ( ULCC ) and $1.7 million for Southwest ( LUV ).

The Treasury sought at least $50,000 per airline for its warrants in Allegiant, Spirit Airlines ( SAVE ) and JetBlue ( JBLU ). Those warrants and others were priced below the current trading prices of the carriers' stocks.

Southwest Airlines ( LUV ) and Delta Air Lines ( DAL ) declined to comment, while other airlines did not immediately respond to requests for comment.

The U.S. government also extended $25 billion in low-cost loans to airlines.

The 2020 pandemic prompted a historic collapse in air travel demand. U.S. air passenger travel fell by 60% in 2020 to its lowest level since 1984, down more than 550 million passengers, as airlines slashed costs and struggled to survive.